Question

two ecosystems, ecosystem x and ecosystem y, are destroyed by different natural disasters.
ecosystem x is destroyed by a glacial retreat, leaving behind only bare rock and gravel.
ecosystem y is destroyed by a severe forest fire that burns all trees but leaves the soil and root systems intact.
which option correctly predicts the type of ecological succession that will occur in each ecosystem?

a.
x: secondary succession;
y: primary succession

b.
x: secondary succession;
y: secondary succession

c.
x: primary succession;
y: secondary succession

d.
x: primary succession;
y: primary succession

Explanation:

To determine the type of ecological succession, we recall:

• Primary Succession: Occurs on newly exposed, lifeless substrates (e.g., bare rock after glacial retreat) with no soil or organic matter.
• Secondary Succession: Occurs in areas where a disturbance (e.g., forest fire) destroys life but leaves soil/root systems intact.

For Ecosystem X (glacial retreat, bare rock): No soil exists, so it undergoes Primary Succession.
For Ecosystem Y (forest fire, soil/roots intact): Soil remains, so it undergoes Secondary Succession.

This matches option C.

Answer:

C. X: Primary Succession; Y: Secondary Succession